First time witnessing Chikan here

Hey guys, long time lurker here. I have been now in Japan for almost 3 years and while I’ve seen multiple incidents of this in social media, this was the first time seeing it in person. Basically I sit in the train and in front of me a what I believed to be a school girl wearing a miniskirt and sleeping, next to her a male in his 30s with his backpack on his lap, one hand on his phone and the other one on his side close to his leg, with his finger quite literally stretching to touch the leg of this girl… I made physical contact with him and pretended to be recording but later more people entered the train and got in between us. I felt really bad for not actually doing anything but I wasn’t sure what to do in such a situation. Should I yell “Chikan” or what ? My blood was boiling… guy wasn’t even entirely bad looking and quite tall, surely he could get a girl, why do this ?

by Crimsye